Ventricaria (Siphonocladales-Cladophorales complex, Chlorophyta), a new genus for Valonia ventricosa

Phycologia ◽  
1988 ◽  
Vol 27 (1) ◽  
pp. 103-108 ◽  
Author(s):  
Jeanine L. Olsen ◽  
John A. West
Keyword(s):  
New Genus ◽  
Valonia Ventricosa

On the cross-sectional shape of the cellulose crystallites in the tunicate Halocynthia papillosa

1990 ◽  
Vol 48 (3) ◽  
pp. 566-567
Author(s):  
J.-F. Revol ◽  
Y. Van Daele ◽  
F. Gaill
Keyword(s):  
Contrast Imaging ◽  
Animal Kingdom ◽  
Bright Field ◽  
Field Mode ◽  
Cross Sectional ◽  
Ultrathin Sections ◽  
The Cross ◽  
Sectional Shape ◽  
Valonia Ventricosa ◽  
C Nmr

The only form of cellulose which could unequivocally be ascribed to the animal kingdom is the tunicin that occurs in the tests of the tunicates. Recently, high-resolution solid-state l3C NMR revealed that tunicin belongs to the Iβ form of cellulose as opposed to the Iα form found in Valonia and bacterial celluloses. The high perfection of the tunicin crystallites led us to study its crosssectional shape and to compare it with the shape of those in Valonia ventricosa (V.v.), the goal being to relate the cross-section of cellulose crystallites with the two allomorphs Iα and Iβ.In the present work the source of tunicin was the test of the ascidian Halocvnthia papillosa (H.p.). Diffraction contrast imaging in the bright field mode was applied on ultrathin sections of the V.v. cell wall and H.p. test with cellulose crystallites perpendicular to the plane of the sections. The electron microscope, a Philips 400T, was operated at 120 kV in a low intensity beam condition.

Patellaria: A new genus in the Chenopodiaceae

1976 ◽  
Vol 87 (5) ◽  
pp. 289-292
Author(s):  
J. T. Williams ◽  
A. J. Scott ◽  
B. V. Ford-Lloyd
Keyword(s):  
New Genus
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